Grantz is the boss of mission 4 in 19XX: The War Against Destiny.
Grantz is a submarine vessel. It will use the many guns on it's body to attack, all of which can be destroyed, rendering the boss defenseless. After the bridge is destroyed, however, the boss will turn around a reveal it's bottom to continue the fight. It has many more guns to attack and for the player to destroy. It will also release small satellites which gives extra medals when shot, homing missiles from the top and rockets from the sides, while the core on the top gets exposed and shoots as well.